We love AS Music
At Music the service was outstanding, the resort was very quiet over all, the busses were only crowded at peak times and at those times the resort often had it's own bus instead of sharing with the other All Stars. The room was very clean and well maintained. Mousekeeping was outstanding.
We stayed at POP the next trip we took. Because of all the hype it gets we figured if we loved AS Music then POP would just be that much better. It wasn't. It wasn't bad, but it wasn't the same level of quality or service we got at Music. Busses are the most common thing I see people say is great about POP. Our busses at POP were always more crowded than what we experienced when we stayed at AS Music. And some of the waits for busses were really, really long compared to what we experienced when we stayed at Music. We were there at similar times of the year.
Next trip we are planning to stay in a family suite at AoA so we'll see how it stands up to our experience at AS Music.